Meager
Inadequate is an example.
Useless is another word for ineffective. Additional synonyms include inadequate, powerless, futile and unproductive.
Target as in target quantity
Ambo
obi
A word that means negative and starts with "de" is "deficient." It conveys a sense of lacking or being inadequate in quality or quantity. Another option could be "detrimental," which implies causing harm or damage.
Inadequate is an example.
Quantity AND QUARTZ
dosage, quantity
Did you mean insufficient? If so: Not enough, inadequate.
short - They were short on experience.
Useless is another word for ineffective. Additional synonyms include inadequate, powerless, futile and unproductive.
Another word starting with g is gloominess
Target as in target quantity
Bulk
An abundary is another word for an abundance, an overflowing quantity of something.
Finish is another word for completion starting with the letter F.