to strike, to hit, to beat, to knock, to pound, to bang, to slap, to spank, to tap, to pat, to clap (one's hands), to play (the drums), to attack, to bash, to criticize, to censure, to flame (on the Internet), to sound out (someone's views), to pound (meat or fish), to chop into small pieces, to beat down the price, to talk (big, bad, idly, etc.), to call, to invoke (e.g. a function)
叩く【はたく】
to dust, to remove dust, to slap, to hit (with the palm), to use up money