(physics) Of or relating to a half-metal.

Happening hourly, but at 30 minutes past each hour; ie, 08:30, 09:30 etc. / Happening on the hour and at 30 minutes after the hour. / (soccer) At thirty minutes into a half.

The onager.

Poorly or incompetently done. / desultory

Produced in an incompetent or desultory manner, or of something lacking in quality or substance; of low rank; incompetent.

(fantasy) A person who is half elven and half human by birth.

(historical) A former British gold coin having a value of ten shillings.

The moon in its first or last quarter when only half the visible face is illuminated; a quarter moon. / Anything shaped like a crescent, especially the base of a fingernail. / A type of cookie

(cricket) A ball bowled so as to pitch roughly half way down the wicket, ie. half-way between batsman and bowler. (From a slow bowler this is a poor delivery, likely to be hit to the boundary.)

A person, especially a child, with only one living parent.