thick as thieves

come thick and fast

To arrive rapidly in large groups.

lay it on thick

To exaggerate or overstate a feeling or emotion.

thick and thin

Both good and bad times.

thick and threefold

In quick succession, or in great numbers.

thick end

Most; the greater part (of an amount of money).

thick of things

A central or major role in a situation; a position in which one is surrounded by or very involved in complex, changing events.

thick skin

Ability to take criticism or harsh behavior without being easily offended.

through thick and thin

Through all (especially grim, rough and difficult) conditions; in all weathers.