رسخ

رَسَخَ(n. ac.
رُسُوْخ)
a. Was, became firm, fixed, steady, solid; was
established; was well-rooted, well-grounded.
b. Was dry; dried up; caked.
c. Fell (rain).
أَرْسَخَa. Rendered firm &c; fixed, steadied; established
consolidated.
b. Fixed in, graved, impressed on the memory.

رَاْسِخ
( pl.
reg. )
a. Firm, fixed, steady, stable; established; well-rooted
well-grounded ( in knowledge ).