can't make heads or tails of

can't make heads or tails (out) of someone or something

Fig. [to be] unable to understand someone or something. (Also with cannot.) John is so strange. I can't make heads or tails of him. Do this report again. I can't make heads or tails out of it.
See also: head, make, of, tail
References in periodicals archive ?
Biologists can't make heads or tails of its spawning habits, which adds to the mystique of the fish and the bane of the angler.
Full browser ?