1) one of a pair of long, narrow organs on the heads of insects, shellfish etc, used as a feeler (antenna)

2) (pl unchanged) a vegetable with many white or purple heads of flowers like small cauliflowers (broccoli)

3) one of the hard, pointed, usually curved parts on the heads of cattle, deer and some other animals (horn)

4) the top of a mountain; the highest point; a meeting between heads of state (summit)