in; inside; enclosed or encased by before (a period of time) has elapsed: within a week not beyond the limits of; not differing by more than (a specified amount) from: live within your means, within seconds of the world record
inside; internally
WordReference Random House Learner's Dictionary of American English © 2026
with•in /wɪðˈɪn, wɪθ-/USA pronunciation
prep.
adv.
WordReference Random House Unabridged Dictionary of American English © 2026- in or into the interior of;
inside:The noise came from within the house. - in the limits of;
not beyond:to live within one's income. - in the field, sphere, or scope of:within the family; not within my power.
adv.
- in or into an interior or inner part:They proceeded within.
- in the mind, heart, or soul;
inwardly:listening to the voice within.
with•in
(wiᵺ in′, with-),USA pronunciation adv.
prep.
n.
- in or into the interior or inner part;
inside. - in or into a house, building, etc.;
indoors:The fire was burning on the hearth within. - on, or as regards, the inside;
internally. - inside an enclosed place, area, room, etc.:He was startled by a cry from within.
- in the mind, heart, or soul;
inwardly.
prep.
- in or into the interior of or the parts or space enclosed by:within city walls.
- inside of;
in. - in the compass or limits of;
not beyond:within view; to live within one's income. - at or to some point not beyond, as in length or distance;
not farther than:within a radius of a mile. - at or to some amount or degree not exceeding:within two degrees of freezing.
- in the course or period of, as in time:within one's memory; within three minutes.
- inside of the limits fixed or required by;
not transgressing:within the law. - in the field, sphere, or scope of:within the family; within one's power.
n.
- the inside of a place, space, or building.
- Middle English withinne (preposition and adverb, adverbial), Old English withinnan (adverb, adverbial), equivalent. to with with- + innan from within, equivalent. to in in + -an suffix of motion from bef. 1000
Collins Concise English Dictionary © HarperCollins Publishers::
'within the body' also found in these entries (note: many are not synonyms or translations):
auscultation
- autogenous
- autointoxication
- autotoxin
- cavity
- dysbarism
- elaborate
- electrolyte
- endosymbiont
- endosymbiosis
- entozoic
- entozoon
- epibiotic
- grasserie
- hole
- infix
- interoceptor
- inward
- kA
- lithic
- loggia
- murmur
- ovoviviparous
- pharmacodynamics
- plaque
- prodrug
- proprioceptor
- retention
- stethoscope
- vapor