American Heritage Dictionary
(5)
Century Dictionary
(2)
GNU Webster's 1913
(1)
WordNet
(2)
Elsewhere on the web
The governor of this garrison has joined me to your escort; and it will be a duty I shall gladly undertake, to render your travel lightsome, and your perils trivial May we," answered Isabel, "request to know to whom we shall be so obliged You may call me Mr. Barton," replied he, "a minister of the church by the laying on the hands of the presbytery.— The Loyalists, Vol. 1-3 An Historical Novel
XLVII If to this frame of mine in spring's first hour When o'er the moor the lightsome mists do curl Might but be lent the shape of some fair flower Haply thou 'dst deign to pluck me, cruel girl Okikaze.— Japanese Literature Including Selections from Genji Monogatari and Classical Poetry and Drama of Japan
As a locust-leaf: The small delicate leaflets of the compound locust-leaf seem always in a "lightsome" movement 138.— The Vision of Sir Launfal And Other Poems by James Russell Lowell; Edited with an Introduction and Notes by Julian W. Abernethy, PH.D.
This line at first read: "With the lightsome," etc. Why did Lowell's refining taste strike out "the 216.— The Vision of Sir Launfal And Other Poems by James Russell Lowell; Edited with an Introduction and Notes by Julian W. Abernethy, PH.D.
18:9): "The commandment of the Lord is lightsome, enlightening the eyes."— Summa Theologica, Part I-II (Pars Prima Secundae) From the Complete American Edition

Century Dictionary (1)
Bubble size: how much this word was used in a year
Bubble height: used more or less than expected, vs. all uses evenly distributed
You can expect to see this word a few times a year.