na-adjective
wishful; hopeful (but not necessarily realistic)
Describes thinking or statements based on hope rather than evidence; often used in phrases like 希望的観測 (wishful thinking).
彼の予測は希望的観測に過ぎない。
His prediction is nothing more than wishful thinking.
希望的発言は避けて、事実だけを述べてください。
Please avoid wishful remarks and state only the facts.
楽観的 means 'optimistic' in a general sense; 希望的 often carries a nuance of being unrealistic or not grounded in fact.
Derived from 希望 (hope) + 的 (adjectival suffix), forming a na-adjective meaning 'wishful' or 'hopeful'.