Keyword
What KeyWord is found in the definitions of each of the following?

503 clock, cuff, darn, hosiery, anklet (5 letters)
504 mukluk, purr, ricotta, una corda, powder puff (4 letters)
505 nugget, thickset, concretion, sublimate, terra firma (5 letters)
506 anon, erelong, shortly, upcoming, presently (4 letters)
507 acidulous, verjuice, tart, amarelle, acerbic (4 letters)
508 wellhead, whencesoever, glim, origin, provenience (6 letters)
509 lean, afford, fifth wheel, parsimonious, superfluous (5 letters)
510 spanakopita, oysters Rockefeller, oxalic acid, chenopod, Florentine (7 letters)
511 acanthoid, swayback, three-quarter binding, thorn, epidural (5 letters)
512 splay, smear, unfurl, trowel, disseminated (6 letters)
513 pounce, fountain, May Day, vernal, Igor Stravinsky (6 letters)
514 Hebe, bound, clipboard, geyser, trampoline (6 letters)
515 pen, ink sac, calamari, cephalopod, dibranchiate (5 letters)
516 caduceus, alpenstock, crosier, mace, walking stick (5 letters)
517 exeunt, mise en scene, prepupa, proscenia, gradation (5 letters)
518 nova, Procyon, astral, headliner, visual binary (4 letters)
519 sauna, stoker, calliope, solfatara, water hammer (5 letters)
520 hush, becalm, airless, impassive, quiescent (5 letters)
521 cardia, rennet, gastrotomy, collywobbles, tripe (7 letters)
522 anode, wareroom, cryobank, fat cell, glove compartment (7 letters)
523 flaw, haboob, trysail, northeaster, Flying Dutchman (5 letters)
524 rectus, beeline, linear, schuss, virgate (8 letters)
525 minimax, cover-up, diversion, board game, full-court press (8 letters)
526 emphasis, hot seat, burnout, battle fatigue, breaking point (6 letters)
527 adamant, obdurate, headstrong, pertinacious, pigheaded (8 letters)

Answers: 503. socks, 504. soft, 505. solid, 506. soon, 507. sour, 508. source, 509. spare, 510. spinach, 511. spine, 512. spread, 513. spring, 514. spring, 515. squid, 516. staff, 517. stage, 518. star, 519. steam, 520. still, 521. stomach, 522. storage, 523. storm, 524. straight, 525. strategy, 526. stress, 527. stubborn,

... or try our companion Rhyme-n-Reason