From WordNet (r) 2.0 (August 2003) [wn]:
endless
adj 1: tiresomely long; seemingly without end; "endless debates";
"an endless conversation"; "the wait seemed eternal";
"eternal quarreling"; "an interminable sermon" [syn:
eternal, interminable]
2: infinitely great in number; "endless waves"
3: having no known beginning and presumably no end; "the
dateless rise and fall of the tides"; "time is endless";
"sempiternal truth" [syn: dateless, sempiternal]
4: having the ends united so as to form a continuous whole; "an
endless chain"
5: occurring so frequently as to seem ceaseless or
uninterrupted; "a child's incessant questions"; "your
perpetual (or continual) complaints" [syn: incessant,
perpetual]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Endless \End"less\, a. [AS. endele['a]s. See End.]
1. Without end; having no end or conclusion; perpetual;
interminable; -- applied to length, and to duration; as,
an endless line; endless time; endless bliss; endless
praise; endless clamor.
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2. Infinite; excessive; unlimited. --Shak.
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3. Without profitable end; fruitless; unsatisfying. [R.] "All
loves are endless." --Beau. & Fl.
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4. Void of design; objectless; as, an endless pursuit.
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5. having a linear or ribbonlike form with the two ends
connected together, such as in a circle, ellipse, torus,
or any other closed loop. Belts or chains used in drive
mechanisms are considered endless in this sense. See
endless chain.
[PJC]
Endless chain, a chain which is made continuous by uniting
its two ends.
Endless screw. (Mech.) See under Screw.
Syn: Eternal; everlasting; interminable; infinite; unlimited;
incessant; perpetual; uninterrupted; continual;
unceasing; unending; boundless; undying; imperishable.
[1913 Webster]