1 twofold, paired, coupled, duplicate(d), doubled:
The forms banned and banning are spelt with a double n .
2 folded or doubled or bent over, overlapped, two-ply:
This wound needs a double bandage.
3 dual, twofold, ambiguous, double-barrelled:
He pronounced it 'de-seat', giving deceit a double meaning.
The plant had grown to double its size.
5 deceitful, dishonest, treacherous, traitorous, insincere, hypocritical, double-dealing, false:
It was Maria who exposed Fernando as a double agent.
6 duplicate, replicate; copy; increase, enlarge; magnify:
We'll have to double our milk order.
7 twin, duplicate, copy, replica, facsimile, clone, copy, counterpart, doppelgänger, look-alike, stand-in, understudy, Slang (dead) ringer, spitting image or spit and image:
He could be Clint Eastwood's double.
8 at or on the double. quickly, on the run, at full speed or tilt, briskly, immediately, at once, without delay, Slang p.d.q. (= 'prety damned quick'):
Put down that book and come over here on the double!