late 14c., plesire, "source of enjoyment, pleasing quality or thing, that which pleases or gratifies the senses or the mind," from Old French plesir, also plaisir "enjoyment, delight, desire, will" (12c.), from noun use of infinitive plaisir (v.) "to please," from Latin placere "to please, give pleasure, be approved" (see please (v.)).
Also from late 14c. as "discretion, will, desire, preference," as in at (one's) pleasure "when one wishes." From mid-15c. as "gratification; feeling of enjoyment, liking." The meaning "sensual gratification" is from early 15c. That of "indulgence of the appetites as the chief object of life" is attested from 1520s. The ending was altered in Middle English by influence of words in -ure (measure, etc.).
Old English secan "inquire, search for; pursue; long for, wish for, desire; look for, expect from," influenced by Old Norse soekja, both from Proto-Germanic *sakanan (source also of Old Saxon sokian, Old Frisian seka, Middle Dutch soekan, Old High German suohhan, German suchen, Gothic sokjan), from PIE *sag-yo-, from root *sag- "to track down, seek out" (source also of Latin sagire "to perceive quickly or keenly," sagus "presaging, predicting," Old Irish saigim "seek"). The natural modern form of the Anglo-Saxon word as uninfluenced by Norse is in beseech. Related: Sought; seeking.