tor
Latinone who, agent noun
About This Root
The element tor comes from Latin -tor, the agent-noun suffix meaning 'one who does (the action of the verb).' It is not a freestanding root with its own meaning the way port (carry) or rupt (break) are. Instead it is a builder: attach -tor to a verb stem and you get the person (or thing) that performs that verb. Latin actor = one who acts; doctor = one who teaches (from docēre, to teach); narrator = one who narrates. English inherited huge numbers of these directly, and the related ending -or does the same job (governor, inventor, editor).
Because -tor turns verbs into doers, the words in this small group are best understood by first finding the verb hiding inside them. signatory packs in signāre (to sign): a signatory is 'one who signs' — most often a country that has signed a treaty. primogenitor combines primo- (first) with the gen- of gignere/genitus (to beget): the 'first begetter,' the founding ancestor of a family line. In both, the -tor/-ory ending simply says 'the one who does this.'
The odd member is moratorium. It is built not on a person but on a place/instrument idea: from morārī (to delay), via the related -torium ending (as in auditorium, 'a place for hearing'). A moratorium is, loosely, 'a thing that produces delay' — and in modern use it means an official, agreed pause: a moratorium on executions, a moratorium on new construction. The delaying verb morā- is the heart of it; the -torium machinery turns it into a formal, declarable suspension.
The lesson of this group is a reading habit rather than a single meaning: when a long Latinate word ends in -tor, -tory, -torium, look for the verb stem before it, and read the ending as 'the one (or thing, or place) that does it.'
Read -tor as 'one who does it': act + or = actor, narrate + or = narrator. Find the verb hiding before the -tor/-tory/-torium ending and the word unlocks: signatory = one who signs.
Core Words Deep Dive
The few words from this family worth telling in full — one by one.
signāre (to sign) + -tor/-ory (one who) = 'one who signs.' The most useful, modern member. A signatory is a party that has put its name to a formal agreement — very often a country bound by an international treaty (each signatory state). It works as both a noun and an adjective (the signatory nations).
The surprising member: not 'one who does X' but 'a thing producing delay,' from morārī (to delay) + the -torium ending. In modern use it means an official, agreed suspension of some activity — usually announced and temporary: a moratorium on the death penalty, on logging, on debt repayment. Pair it with declare / impose / lift to use it naturally.
primo- (first) + genit- (beget, from gignere) + -or (one who) = 'the first begetter,' the founding ancestor of a family or line. A literary, formal word. Note its cousin primogeniture — the right of the firstborn to inherit — which shares the primo- + gen- core but ends differently.