The Collaborative International Dictionary
Thick \Thick\, n.
-
The thickest part, or the time when anything is thickest.
In the thick of the dust and smoke.
--Knolles. -
A thicket; as, gloomy thicks. [Obs.]
--Drayton.Through the thick they heard one rudely rush.
--Spenser.He through a little window cast his sight Through thick of bars, that gave a scanty light.
--Dryden.Thick-and-thin block (Naut.), a fiddle block. See under Fiddle.
Through thick and thin, through all obstacles and difficulties, both great and small.
Through thick and thin she followed him.
--Hudibras.He became the panegyrist, through thick and thin, of a military frenzy.
--Coleridge.
Wiktionary
n. (context nautical English) A fiddle block.