the.com/lack
The conspicuous shape of a thing by the size of its absence.
means To be without something needed or wanted, or the state of that shortage itself.
from From Middle Dutch and Low German lak, meaning deficiency or fault — the medieval English absorbed it, fittingly, to fill a gap.
Verb and nounYou can lack a thing or feel the lack.
Cousin wordLackluster: literally missing its shine.
Not lackingLackey is unrelated, despite sounding servile.