Origin: bef. 1000; (n.) ME
glem(
e), OE
glǣm; c. OHG
gleimo glowworm; akin to OS
glīmo brightness; (v.) ME, deriv. of the n.
See glimmer, glimpse 
Related forms: gleam⋅ing⋅ly, adverb
gleamless, adjective
Synonyms:
1. Gleam, glimmer, beam, ray are terms for a stream of light. Gleam denotes a not very brilliant, intermittent or nondirectional stream of light. Glimmer indicates a nondirectional light that is feeble and unsteady: a faint glimmer of moonlight. Beam usually means a directional, and therefore smaller, stream: the beam from a searchlight. Ray usually implies a still smaller amount of light than a beam, a single line of light: a ray through a pinprick in a window shade. 4. shine, glimmer, flash, glitter, sparkle, beam.
[gleem] 