unthriving

As a noun terms

is .

As an adjective unthriving is

failing to thrive; weak or sickly.

As adjectives the difference between sickly and unthriving

is that sickly is frequently ill; often in poor health; given to becoming ill while unthriving is failing to thrive; weak or sickly.

As a verb sickly

is to make sickly.

As an adverb sickly

is in a sick manner.

As adjectives the difference between weak and unthriving

is that weak is lacking in force (usually strength) or ability while unthriving is failing to thrive; weak or sickly.

As a verb thrive

is to grow or increase stature; to grow vigorously or luxuriantly, to flourish.

As an adjective unthriving is

failing to thrive; weak or sickly.