within
Pronunciation: /wɪðˈɪn/
preposition
- 1inside (something): the spread of fire within the building
- inside the range of (an area or boundary): property located within the green belt
- inside the range of (a specified action or perception): we were within sight of the finish
- inside the bounds set by (a concept, argument, etc.): full cooperation within the terms of the treaty

Origin:
late Old English withinnan 'on the inside'