n. 25B6; noun
fastened with nails : TACK, spike, pin, rivet; hobnail.
biting her nails : FINGERNAIL, thumbnail, toenail.
ungual.
25B6; verb
a board was nailed to the wall : FASTEN, attach, fix, affix, secure, tack, hammer, pin.
(informal) nailing suspects : CATCH, capture, apprehend, arrest, seize; informal collar, nab, cop, pull in, pick up; Brit. informal nick.
the pictures had nailed the lie : EXPOSE, reveal, uncover, unmask, bring to light, detect, identify.
25A0; hard as nails CALLOUS, hard-hearted, heartless, unfeeling, unsympathetic, uncaring, insensitive, unsentimental, hardbitten, tough, lacking compassion.
25A0; on the nail IMMEDIATELY, at once, without delay, straight away, right away, promptly, directly, now, this minute; N. Amer. on the barrelhead.