caller (n.)youdaoicibaDictYouDict
c. 1500, "one who proclaims," agent noun from call (v.). Meaning "one who announces step changes at a dance" is recorded from 1882; "one who places a telephone call," 1898. Meaning "a social visitor" is attested from 1786.
dime (n.)youdaoicibaDictYouDict
chosen 1786 as name for U.S. 10 cent coin, from dime "a tenth, tithe" (late 14c.), from Old French disme (Modern French dîme) "a tenth part," from Latin decima (pars) "tenth (part)," from decem "ten" (see ten).

The verb meaning "to inform" (on someone) is 1960s, from the then-cost of a pay phone call. A dime a dozen "almost worthless" first recorded 1930. Phrase stop on a dime attested by 1954 (a dime being the physically smallest unit of U.S. currency).
pager (n.)youdaoicibaDictYouDict
"device that emits a signal when activated by a telephone call," 1968, agent noun from page (v.1).
person (n.)youdaoicibaDictYouDict
early 13c., from Old French persone "human being, anyone, person" (12c., Modern French personne) and directly from Latin persona "human being, person, personage; a part in a drama, assumed character," originally "mask, false face," such as those of wood or clay worn by the actors in later Roman theater. OED offers the general 19c. explanation of persona as "related to" Latin personare "to sound through" (i.e. the mask as something spoken through and perhaps amplifying the voice), "but the long o makes a difficulty ...." Klein and Barnhart say it is possibly borrowed from Etruscan phersu "mask." Klein goes on to say this is ultimately of Greek origin and compares Persephone.

Of corporate entities from mid-15c. The use of -person to replace -man in compounds and avoid alleged sexist connotations is first recorded 1971 (in chairperson). In person "by bodily presence" is from 1560s. Person-to-person first recorded 1919, originally of telephone calls.
tap (n.3)youdaoicibaDictYouDict
"device to listen in secretly on telephone calls," 1923, from tap (v.2) in the "listen secretly" sense.
on-hookyoudaoicibaDictYouDict
"(Of a telephone) having the receiver resting on the hook; chiefly in on-hook dialling, a facility for initiating a telephone call without lifting the receiver", 1970s; earliest use found in The New York Times.