The headword verb is so rare as to have been overlooked by LSJ until the 1968 Supplement. There it does appear, with both the present gloss (for which cf. ps.-Zonaras 1292.10, and see chi 337) and the more elaborate one from the ninth-century grammarian Theognostus (in a passage about terms with the prefix lai, Canones 27.2): 'producing a sound through the mouth against the breast'. Note also the suspiciously similar laiqaru/zein, glossed by Hesychius lambda131 as lamurw=sai, diapra/casqai.