Aculeus -ei: a prickle; a small sharp point; specifically, an ovipositor, especially when sting-like, as in Hymenoptera; in male Tipulidae a slender, horny, often curved and pointed piece, projected when the forceps is open.

Acuminate: tapering to a long point.

Acupunctate: a surface with fine punctures as if made with a needle.

Acutangulate: forming, or meeting in an acute angle.

Acute: pointed: terminating in or forming less than a right angle.

Acutilingual: with a sharp pointed tongue or mouth structure, as in some bees.

Acutilingues: bees with a short pointed tongue: see obtusilingues.

Addorsal: close to but not quite on the middle of the dorsum.

Addorsal line: in caterpillars, is longitudinal, a little to one side of the dorsal and between it and the subdorsal line.

Adductor: applied to muscles that draw an appendage to the body or bring parts into apposition: see abductor.