недостатъчен означава в английски

deficient▼(insufficient or inadequate in amount)
adjective
[UK: dɪ.ˈfɪʃnt] [US: də.ˈfɪ.ʃənt]

insufficient▼adjective
[UK: ˌɪn.sə.ˈfɪʃnt] [US: ˌɪn.sə.ˈfɪ.ʃənt]

scanty [scantier, scantiest]▼(somewhat less than is needed in amplitude or extent)
adjective
[UK: ˈskæn.ti] [US: ˈskæn.ti]

scarce [scarcer, scarcest]▼(something rare, in low supply)
adjective
[UK: skeəs] [US: ˈskers]

skimpy [skimpier, skimpiest]▼(small or inadequate; not generous)
adjective
[UK: ˈskɪm.pi] [US: ˈskɪm.pi]