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Headroom

noun

Noun

1
The vertical clearance above someone's head, as in a tunnel, doorway etc; room (space) for one's head. countable, uncountable
2
the capacity of a system to reproduce loud sounds without distortion wordnet
3
The vertical measurement, top to bottom, for example for clearance under a bridge. countable, uncountable
"With a rare and beautiful ease one can now ring up a boffin, as I did the other day, and say: "As a price for not opposing our Parliamentary Powers for a new marshalling yard, the Council at X demands that the bridge over X Lane shall have 16 ft. 6 in. headroom. This means steepening our gradient from 1 in 70 to 1 in 65 for half a mile on a 20-chain curve. What difference will this make to the loads of Type "2", "3" and "4" diesels please?". Back comes the answer."
4
vertical space available to allow easy passage under something wordnet
5
The ability of a system to reproduce loud sounds free of distortion; dynamic headroom. countable, uncountable
"[…] the difference between signal-to-noise ratio and overload reserve (headroom) as well as noise (safety) margin (footroom)."

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6
The distance between the actual performance of an algorithm and its maximum possible performance. countable, uncountable
7
Synonym of headspace (“space between the top of the contents of a container and its seal”). countable, uncountable
"For whole pickles and fruit preserves, leave no less than ½ inch of headroom at the top of the jars […]"

From head + room.

Unscramble this word: headroom