Blind–as–a–bat

any of numerous flying mammals of the order Chiroptera, of worldwide distribution in tropical and temperate regions, having modified forelimbs that serve as wings and are covered with a membranous skin extending to the hind limbs.
blind as a bat, nearly or completely blind; having very poor vision:
Anyone can tell that he’s blind as a bat, but he won’t wear glasses.
have bats in one’s belfry, Informal. to have crazy ideas; be very peculiar, erratic, or foolish:
If you think you can row across the ocean in that boat, you have bats in your belfry.
noun
any of various types of club with a handle, used to hit the ball in certain sports, such as cricket, baseball, or table tennis
a flat round club with a short handle, resembling a table-tennis bat, used by a man on the ground to guide the pilot of an aircraft when taxiing
(cricket) short for batsman
any stout stick, esp a wooden one
(informal) a blow from such a stick
(Austral) a small board used for tossing the coins in the game of two-up
(US & Canadian, slang) a drinking spree; binge
(slang) speed; rate; pace: they went at a fair bat
another word for batting (sense 1)
(cricket) carry one’s bat, (of an opening batsman) to reach the end of an innings without being dismissed
off one’s own bat

of one’s own accord; without being prompted by someone else
by one’s own unaided efforts

(US & Canadian, informal) off the bat, right off the bat, immediately; without hesitation
verb bats, batting, batted
(transitive) to strike with or as if with a bat
(intransitive) (sport) (of a player or a team) to take a turn at batting
noun
any placental mammal of the order Chiroptera, being a nocturnal mouselike animal flying with a pair of membranous wings (patagia). The group is divided into the Megachiroptera (fruit bats) and Microchiroptera (insectivorous bats) related adjective chiropteran
(slang) an irritating or eccentric woman (esp in the phrase old bat)
blind as a bat, having extremely poor eyesight
(informal) have bats in the belfry, have bats in one’s belfry, to be mad or eccentric; have strange ideas
(slang) like a bat out of hell, very quickly
verb (transitive) bats, batting, batted
to wink or flutter (one’s eyelids)
(informal) not bat an eye, not bat an eyelid, to show no surprise or concern
n.
v.

A prostitute; a loose woman •Probably so called because she works at night (1600s+)
old bat
A woman, esp an ugly one (1880s+)
A spree; carousal; binge (1840s+)

Bachelor of Arts in Teaching
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Quite blind; also, unaware. For example, Without my glasses I’m blind as a bat, or I had no idea they wanted me to take over his job; I was blind as a bat. This simile, based on the erroneous idea that the bat’s erratic flight means it cannot see properly, has survived even though it is now known that bats have a sophisticated built-in sonar system. [ Late 1500s ]

bat an eye
bat around
bat one thousand
bat the breeze