long i

noun2

1. •
   the English vowel sound /aɪ/ in the words "fine" and "like", often conventionally written ⟨ī⟩. (The presence of a long vowel is often signaled in spelling by a silent e that follows it, as in the examples here, or by the fact that a subsequent consonant is single rather than doubled, as for example in siting versus sitting).
2. •
   a tall variant of the letter i, ⟨ꟾ⟩, used in all-capital Latin inscriptions and manuscripts in classical antiquity and the Early Middle Ages for a long vowel /iː/. (Other long vowels were marked with apices.)