Blind level

(Mining) a level or drainage gallery which has a vertical shaft at each end, and acts as an inverted siphon.

See also: Blind

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
In reply, India comfortably chased down the target in just 34.5 overs, with Haryana's Deepak Malik (B3 - blind level 3) scoring the highest runs of 79 off 71 balls.
“With the large amount of chips and long blind levels my strategy for day one was to chip up slowly, not risk chips.
And it can really hurt if you already were short-stacked in relation to the blind levels.
The 15-minute blind levels and a 3k starting stack makes for quite a lot of play and there's no need to panic early on.
DALEY DREAD Blind levels for United after Sessegnon puts Albion ahead, Fellaini equalises and Berahino strikes