groaning

Short definition from Wiktionary

Adjective

1. 1
   That groans.
2. 2
   Heavily laden, as if to creak under the strain.

Noun

1. 1
   A low sound associated with extended suffering, sorrow, and toil.
2. 2
   Ellipsis of groaning time (“childbirth, labour”).

Verb

1. 1
   present participle and gerund of groan