EXPLICIT.

Synonym:

express.

Both explicit and express are opposed to what is merely implicit[163] or implied. That which is explicit is unfolded, so that it may not be obscure, doubtful, or ambiguous; that which is express is uttered or stated so decidedly that it may not be forgotten nor overlooked. An explicit statement is too clear to be misunderstood; an express command is too emphatic to be disregarded. Compare [CLEAR].

Antonyms:

ambiguous,implicit,indefinite,uncertain,
doubtful,implied,indeterminate,vague.

EXTEMPORANEOUS.

Synonyms:

extemporary,impromptu,offhand,
extempore,improvised,unpremeditated.