Math: determine the length of.

Reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities.

synonym: refine.

Dutch: veredelen, verrijken

Bring, lead, or force to abandon a wrong or evil course of life, conduct, and adopt a right one.

synonyms: reclaim, reform, regenerate.

Set straight or right:
— Rectify the inequities in salaries.

synonyms: amend, remediate, remedy, repair.

Roget 246: be straight etc. adj.; have no turning; not incline to either side, not bend to either side, not turn to either side, not deviate to either side; go straight; steer for etc. (directions) 278.    render straight, straighten, rectify; set straight, put straight; unbend, unfold, uncurl etc. 248, unravel etc. 219, unwrap.    ... show more

Roget 658: improve; be better, become better, get better; mend, amend.    advance etc. (progress) 282; ascend etc. 305; increase etc. 35; fructify, ripen, mature; pick up, come about, rally, take a favorable turn; turn over a new leaf, turn the corner; raise one's head, sow one's wild oats; recover etc. 660.    be better etc. adj., be improved by; turn to right account, turn to good account, turn to best account; profit by, reap the benefit of; make good use of, make capital out of; place to good account.    render better, improve, mend, amend, better; ameliorate, meliorate; correct; decrassify^†.    improve upon, refine upon; rectify; enrich, mellow, elaborate, fatten.    promote, cultivate, advance, forward, enhance; bring forward, bring on; foster etc. 707; invigorate etc. (strengthen) 159.    touch up, rub up, brush up, furbish up, bolster up, vamp up, brighten up, warm up; polish, cook, make the most of, set off to advantage; prune; repair etc. (restore) 660; put in order etc. (arrange) 60.    review, revise; make corrections, make improvements etc. n.; doctor etc. (remedy) 662; purify, etc. 652.    relieve, refresh, infuse new blood into, recruit.    reform, remodel, reorganize; new model.    view in a new light, think better of, appeal from Philip drunk to Philip sober.    palliate, mitigate; lessen an evil etc. 36.    ... show more

Roget 660: return to the original state; recover, rally, revive; come come to, come round, come to oneself; pull through, weather the storm, be oneself again; get well, get round, get the better of, get over, get about; rise from one's ashes, rise from the grave; survive etc. (outlive) 110; resume, reappear; come to, come to life again; live again, rise again.    heal, skin over, cicatrize; right itself.    restore, put back, place in statu quo [Lat.]; reinstate, replace, reseat, rehabilitate, reestablish, reestate^†, reinstall.    reconstruct, rebuild, reorganize, reconstitute; reconvert; renew, renovate; regenerate; rejuvenate.    redeem, reclaim, recover, retrieve; rescue etc. (deliver) 672.    redress, recure^†; cure, heal, remedy, doctor, physic, medicate; break of; bring round, set on one's legs.    resuscitate, revive, reanimate, revivify, recall to life; reproduce etc. 163; warm up; reinvigorate, refresh etc. 689.    make whole, redintegrate^†; recoup etc. 790; make good, make all square; rectify, correct; put right, put to rights, set right, set to rights, set straight; set up; put in order etc. (arrange) 60; refit, recruit; fill up, fill up the ranks; reinforce.    repair; put in repair, remanufacture, put in thorough repair, put in complete repair; retouch, refashion, botch^†, vamp, tinker, cobble; do up, patch up, touch up, plaster up, vamp up; darn, finedraw^†, heelpiece^†; stop a gap, stanch, staunch, caulk, calk, careen, splice, bind up wounds.    ... show more

Dutch: herstellen, verhelpen

Make right or correct:
— Rectify the calculation.

synonyms: correct, right.

Dutch: herzien, corrigeren, verbeteren

Convert into direct current.

Dutch: rechtzetten, rectificeren, amenderen, corrigeren