An Etymological Dictionary of Astronomy and Astrophysics

A tract of land completely surrounded by water, and not large enough to be called a → continent (Dictionary.com).

Etymology (EN): M.E. iland, from O.E. igland “island,” from ieg “island;” PIE *akwa- “water,” cf. Pers. âb, → water,

• → land.

Etymology (PE): Âdâk, âdak, adak “island” (Dehxodâ), probably from Proto-Ir. *āpdaka- “placed in water,” from *âp-, → water, cf. Pers. âb,

• da- “to place, put,” cf. Pers. dâdan “to give,” → thesis, + suffix -ka.
  Âbxost, ultimately from āpxvasta-, literally “stricken/pounded by water,” from *āp-, → water, + *xvasta-, from Proto-Ir. *huah- “to strike, to thresh;” cf. Av. (paiti)xv^anh- “to thresh;” Mid.Pers. xwastan “to tread, trample, thresh;” Mod.Pers. xvast “trampled, beaten,” âbxun “island,” šabixun “night attack;” Kurd. xistin, xin-, xa- “to strike, to beat;” Hamedâni xostan/xus-, Esfahâni xosan “to throw.”
  Jaziré loan from Ar. jazirah.
  Tomb “island” in Iranian Hormozgâni dialects.