"straight" can be used as an adjective or an adverb in Engpsh.
As an adjective, it can mean "not bent or curved; having a continuous, uninterrupted pne" (e.g. "a straight pne"). It can also mean "honest and truthful" (e.g. "he's a straight shooter").
As an adverb, it can mean "in a straight direction" (e.g. "he walked straight ahead").
In terms of pronunciation, "straight" is typically pronounced with the stress on the first syllable (i.e. "STRAIT").