مَرْقَبٌ
and
مَرْقَبَةٌ
An elevated place upon which a spy, or watchman, ascends, or stations himself: (S, A, * Msb, K: *) [a structure such as is termed] an
عَلَم, or a hill, upon which one ascends to look from afar: or, according to Sh, the latter signifies a place of observation on the top of a mountain or of a fortress: according to AA, the plural, مَرَاقِبُ, signifies elevated pieces of ground. (TA.)