From Middle English glad, gled, from Old English glæd (“shining; bright; cheerful; glad”), from Proto-Germanic *gladaz (“shiny; gleaming; radiant; happy; glossy; smooth; flat”), from Proto-Indo-European *gʰladʰ-, from *ǵʰelh₂- (“to shine”). Cognate with Scots gled, glaid (“shining; bright; glad”), Saterland Frisian glääd (“smooth; sleek”), West Frisian glêd (“smooth”), Dutch glad (“smooth; sleek; slippery”), German glatt (“smooth; sleek; slippery”), Danish, Norwegian and Swedish glad (“glad; happy; cheerful”), Icelandic glaður (“glad; joyful; cheery”), Latin glaber (“smooth; hairless; bald”), Russian гла́дкий (gládkij, “smooth”). Doublet of glatt.
1
Usually Pleased; happy; gratified.
I'm glad the rain has finally stopped.
I'm always glad to be of service.
4 more examples
I was glad of receiving the tent in time for the camping trip.
I am glad of you. And so I have been since our first encounter.
I'm very glad at this decision because we'd been on the ropes for a while.
I am happy and glad at your success.
2
Obsolete, Usually Having a bright or cheerful appearance; expressing or exciting joy; producing gladness.
Her conversation / More glad to me than to a miser money is.a. 1587, Philippe Sidnei [i.e., Philip Sidney], “(please specify the folio)”, in [Fulke Greville; Matthew Gwinne; John Florio], editors, The Countesse of Pembrokes Arcadia [The New Arcadia], London: […] [John Windet] for William Ponsonbie, published 1590, →OCLC:
Glad Eevening & glad morn crownd the fourth day.1667, John Milton, “Book I”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, →OCLC:
that which gladded all the warrior train1700, [John] Dryden, “Palamon and Arcite: Or, The Knight’s Tale. In Three Books.”, in Fables Ancient and Modern; […], London: […] Jacob Tonson, […], →OCLC:
Each drinks the juice that glads the heart of man.1725, Homer, “Book VII”, in [Alexander Pope], transl., The Odyssey of Homer. […], volume II, London: […] Bernard Lintot, →OCLC:
1 more example
God that glads the lover's heart1922, A. E. Housman, Epithalamium, line 3: