noun.a usually recurring salient thematic element (as in the arts); especially: a dominant idea or central theme

• … the perfidy of men is a motif in several of the stories.
• a decorative motif

noun.a single or repeated design or color

• Animals and flowers as well as trees decorate sixteenth- and seventeenth-century Chinese panels, and each motif had its own meaning.
• These RNA molecules have an intriguing structural motif, absent in normal RNA, that recognizes an amino acid and chemically binds to it, forming a novel type of RNA enzyme, or ribozyme.

noun.a distinctive, usually recurrent, molecular sequence (as of amino acids or base pairs) or structural element (as of secondary protein structures)

• Only about half these genes have recognizable motifs, or DNA-sequence patterns, that suggest possible functions.