(simile) Very stupid; slow to learn or understand.

(simile) Very sly, very cunning.

(Britain, New Zealand, Australia, simile) Very cheap, not costing much.

Alternative form of pure as the driven snow

(chiefly UK and Ireland, idiomatic, vulgar, simile) Extremely happy; obviously satisfied and carefree.

(simile) extremely light, having minimal weight

All the countries of the Indian subcontinent (principally India, Pakistan, Bangladesh, Nepal, and Bhutan) and the Indian Ocean (principally Sri Lanka, Maldives)

(idiomatic, simile, chiefly hyperbolic) Extremely old.

As usual.

As is usually the case; as always.