Semantic ambiguity is part of the specification of the grammar of a language; most, if not all, sentences are semantically ambiguous, but their ambiguity need not be noticed by listeners, and in fact it is typically discovered only by linguistic research. Perceived ambiguity, on the other hand, is a result of the interpretation process, that is defeasible in nature, and may therefore result in more than one interpretation in cases of miscommunication or when the speaker constructs the context appropriately to serve a rhetorical purpose (Poesio 12).
A somewhat different approach to semantic ambiguity, which actually elides into discussion of lexical ambiguity, is presented by Levine, who uses the term "semantic structure ambiguity" to bring in the idea of the framework or pattern, which comprises many parts. The explanatory statement is that "semantic ambiguity can arise at the phrase level from alternative available semantic relationships between/among the constituents of the phrase " (Levine 390).
Lexical ambiguity deals with problematics of meaning of the many parts or constituents that compose the pattern or structure. In Palmer's formulation, lexical semantics, and by implication lexical ambiguity, becomes a subset of semantics and semantic ambiguity inasmuch as it would link multiple "sense relations  associated with the word or lexical item/lexeme and with a lexical structure" (914). Lexic