Synonyms for Extension:

n.

rise, surge, jump, leap, explosion, upsurge, upswing, spurt. distance, access profile, bitmap, batch file, configuration file, checksum, backup, length, ASCII file, cookie, width, bitstream, archive, size. changing room, anteroom, chamber, boiler room, cubicle, airlock, booth, control room, delay, atrium, branch, antechamber. dictation, blue book, blackboard, chalkboard, classwork, all-nighter, long, crib, eraser, exercise book, essay. card, beeper, answering machine, button, 4G, bleeper, 3G, calling card, cell, cameraphone, spread. articles, class, day school, crash course, ed, apprenticeship, correspondence course, doctoral, part, concentration, course, arm. outcome, effect, consequence, side effect, the aftermath, result, end result, influence, impact, the upshot (of something). open, stretch, extend, kick, close, wave, fold your arms/hands, reach out. connection, camber, bend, bicycle lane, carpool lane, corner, bike lane, cloverleaf, chicane, central reservation. date, duration, chapter, countdown, block, epoch, era, day. creditworthiness, creditor, debt collector, foreclose, borrowing, financier, compound interest, borrowing power, creditworthy. hairpiece, extensions, rug, toupee, hair weave, wig. accompaniment (noun)
appurtenance, accessory, addition, consort, auxiliary, fixture, attachment, extra, ornament, addendum, brother, appendage, garnish, accompaniment, adornment, companion, second, appendix, secondary, lieutenant, adjunct.
augmentation (noun)
swelling, annex, amalgamation.
continuation (noun)
perseverance, maintenance, abidingness, protraction, continuance, prolongation, continuation, interminability, persistence.
department (noun)
branch.
distention (noun)
dilation.
duration (noun)
continuance.
enlargement, continuation (noun)
development, delay, addition, extent, distension, branch, increase, orbit, broadening, purview, reach, lengthening, expansion, spread, appendage, compass, protraction, widening, augmentation, annex, scope, arm, elongation, amplification, wing, appendix, sweep, stretching, prolongation, stretch, addendum, adjunct.
expansion (noun)
distension, spreading, crescendo, thickening, burgeoning, development, broadening, engorgement, stretching, dilation, lengthening, widening, amplification, fattening.
extension (noun)
extension service, extension phone, prolongation, reference, denotation, telephone extension, annexe, annex, propagation, wing, elongation, university extension, lengthiness.
extent (noun)
extent, ambit.
increase (noun)
expansion, augmentation, accrual, elevation, inflation, magnification, increment, enlargement, growth, multiplication, increase.

Other synonyms:

creditworthy, creditworthiness, debt collector, purview, compound interest, foreclose, creditor, borrowing power, financier. realm, ambit. extent, borrowing. sphere, compass. scope, orbit. arm. range. compass
reach.
magnitude
size.

Usage examples for extension

  1. But, my dear Baron, will not the German people be alarmed at the consequences of an extension of our possessions over sea? – The Coming Conquest of England by August Niemann
  2. The appearance of commerce on a large scale has depended on the state of agriculture, industry, ways of communication, social and economic conditions and political extension – Essay on the Creative Imagination by Th. Ribot
  3. We then spent a night or two with Mr. Dashwood at Port Darwin, where we were much interested in the population, partly officials of the Eastern Extension Cable Company and partly Chinese. – Fifty-One Years of Victorian Life by Margaret Elizabeth Leigh Child-Villiers, Countess of Jersey