Half of the triangular letter colon ⟨ː⟩ to indicate half of the extra length implied by the full letter colon ⟨ː⟩.
A triangular variant of the letter half colon ⟨ꞏ⟩.
(IPA)half-long, that is, somewhat longer than the norm, but not as long as would be transcribed by ⟨ː⟩.
(superscript ⟨𐞂⟩,IPA) moderate extension of the featured indicated by a diacritic; e.g. [tʰ𐞂] (a t with somewhat lengthy aspiration, e.g. longer than [pʰ]).
The half colon ⟨ˑ⟩ may be contrasted or combined with the colon ⟨ː⟩, for example ⟨aˑ⟩ for a moderate length between short [a] and long [aː], or ⟨aːˑ⟩ for a length between long [aː] and extra-long [aːː].