1794, "an appendix to a work; a thing to be added," from Latin addendum, neuter of addendus "that which is to be added," gerundive of addere "add to, join, attach" (see add (v.)). The classical plural form is addenda.
late 14c., "join or combine (with); attach (to something), adhere," from Old French aploiier "apply, use, attach" (12c., Modern French appliquer), from Latin applicare "attach to, join, connect;" figuratively, "devote (oneself) to, give attention," from ad "to" (see ad-) + plicare "fold" (from PIE root *plek- "to plait").
The etymological sense is "bring things in contact with one another." In English, from c. 1400 as "use or employ" something for a certain purpose." From early 15c. in reference to lotions, plasters, etc., "place in contact with the body," also, of one's mental powers or faculties, "put to work at a task or pursuit." The meaning "seek a job by submitting an application for one" is from 1851. A by-form applicate is recorded from 1530s. Related: Applied; applying.
1690s, "tending to be added," from Late Latin additivus "added, annexed," past-participle adjective from Latin addere "add to, join, attach" (see addition). Alternative addititious "additive, additional" (1748) is from Latin additicius "additional."
"fasten, join, attach," 1530s, from Medieval Latin affixare, frequentative of Latin affigere (past participle affixus) "fasten to, attach," from ad "to" (see ad-) + figere "to fasten" (from PIE root *dheigw- "to stick, fix").
According to OED first used by Scottish writers and thus perhaps the immediate source was French affixer, a temporarily re-Latinized spelling of Old French afichier (Modern French afficher), from a Medieval Latin variant of the Latin verb. The older form in English was affitch (Middle English afficchen, late 14c.), from Old French afichier. Related: Affixed; affixt; affixing.
combining form used from 19c. to represent Latin latus "the side, flank of humans or animals, lateral surface," a word of uncertain origin. The Latin word also was used to express intimacy, attachment, or relationship via the notion of "attach to the side, at the side of."
c. 1400, from Latin aggregatus "associated, united," past participle of aggregare "add to (a flock), lead to a flock, bring together (in a flock)," figuratively "attach, join, include; collect, bring together," from ad "to" (see ad-) + gregare "to collect into a flock, gather," from grex (genitive gregis) "a flock" (from PIE root *ger- "to gather").