What is the meaning of Ter-?

three, threefold

incidental aspect of the passive ambitransitive (intransitive-transitive) verb

momentaneous aspect of the passive intransitive verb

perfective aspect of the passive transitive verb

noun derivative from perfective aspect of the passive transitive verb

potential mood of the passive transitive verb: to be able [base]

used to form the superlative of adjectives and adverbs.

asunder, to pieces, to bits, in two

accidental aspect of the passive intransitive verb

momentane aspect of the passive intransitive verb

perfective aspect of the passive transitive verb

to be able [base]

used to form the superlative of adjectives and adverbs.

Source: wiktionary.org