an indirect reference; something implied or inferred (through an image, word, concept, or oversound of words or meanings)

E.g., in Christian contexts, "Lamb" alludes to Jesus.

similar logic; correspondence; a similarity between like features of two things, forming the basis of a comparison

E.g., describing electricity as a "current" or "flow" of energy is to understand it through analogy to a river.

involving a figure of speech; not literal  (see list of figures of speech)

by the letter; true to fact; plain; straightforward; non-figurative; face-value of meaning; direct reference

a mark that points to, indicates, means, "signifies," something other than itself