In 1646, English polymath Sir Thomas Browne published a rather interesting book entitled Pseudodoxia epidemica, in which he essentially dispelled fake news, correcting common superstitions and errors of the time. The third part of the seven-section tome  dealt with animals, and in it he wrote one sentence about how even veterinarians believe that horses don't have gallbladders. That was the first use of the word veterinarian in the English language (replacing its bizarre predecessor dog-leech), and it only took off from there, now constituting about 0.00012% of all spoken words. Browne borrowed the word from Latin veterinarius, which meant "cattle doctor" (over time, that definition got widened to "animal doctor" in general), and that has an uncertain etymology. It could be from words meaning "old", "to draw", or something else, but we're not completely sure.

The Ancestral Pueblans were an ancient Amerindian civilization famed for their basketmaking and dwellings carved out of stone and clay. Around the year 1400, they began to be in increasing contact with the Navajo people, with whom they had a generally beneficial relationship. However, there was a point when Navajos didn't trust the Pueblans too much because their forebears weren't related. Thus, they called them the anasazi, a word which in their language meant "enemy ancestors" (composed of anaa'i, meaning "enemy", and bizazi, meaning "ancestors". This was borrowed into archaeological terminology in the 1880s when Americans first started exploring local ruins, and soon reached mainstream recognition. The modern-day Pueblans, however, don't like that term and have been trying to rebrand, so there's been a marked drop in usage of the word since the turn of the century.

Acronyms (which must be pronounced as words, unlike initialisms) were pretty rare until World War II, and many abbreviation explanations you hear for etymologies are fake, so that's something to be cautious about. The term acronym was first used in 1940 by literary critic Edwin Muir and took off, peaking in usage in 2004. That was borrowed from German akronym, which was created, by influence of words like homonym and synonym, out of the Ancient Greek word akron, meaning "summit" or "peak", and the suffix -onym, meaning "name". The idea was that an acronym is composed only out of the "peak" (uppercase) letters of the words that compose it. Akron, which is the etymon for the Ohio city name, comes from Proto-Indo-European hkros, which meant "sharp", and -onym derives from the PIE root hnomn, also "name". 

The word diplomacy was first written down by former Irish MP Edmund Burke in 1796. He continued using it for a few years until other authors started picking it up, with usage peaking during World War I. This was borrowed from the French word diplomatie, which is from Modern Latin diplomaticus, meaning "diplomat". Here it gets interesting: that traces to the Latin word diploma, which described the official diplomatic papers that those diplomats received. This had a broader definition of "document conferring a privilege" and is also the etymon of our current English word diploma, which was adopted in the seventeenth century. The Latin term further goes back to Ancient Greek diploma, which meant "license" but more literally could be interpreted as "folded paper" because the root of it all is diplo-, "twofold" (-oma just denoted action). So both diplomacy and diplomas have creases in common.

The first pager was invented in 1921 for use by the Detroit Police Department, but back then they were called beepers and they weren't commercially viable until the 1950s, when the word pager first began to be used in advertising. This term is a noun form of the verb page, which had a definition of "summon someone by name" and has been around since 1904. For a good four hundred years before that, it also meant "attend to", which comes from a previous noun page, meaning "errand boy". Through Old French and maybe Italian, that derives from Latin pagius ("servant"), which traces to Ancient Greek pais, meaning "child". Finally, philologists reconstruct it all as being from the reconstructed Proto-Indo-European root  pehw, or "little". There is no relation to page meaning "sheet of paper" whatsoever.

Gorp is a common word in North American camping and hiking slang describing a combination of nuts, dried fruits, and sometimes candy. Basically, trail mix. Most people assert that it's an acronym for good old raisins and peanuts (two common ingredients of the mixture). Some others claim granola, oats, raisin, and peanuts is the origin, or something else along those lines. However, etymologists aren't even sure it's an acronym at all. For one, there is evidence of gorp being a verb meaning "eat quickly" as far back as the 1910s, way before the food was popularized. Acronym explanations for etymologies are also frequently erroneous, so not much stock should be put into the common interpretation. Despite that murky origin, though, usage of gorp is on the rise these days, probably due to the increased interest in hiking in recent years.