| air hole | a hole that allows the passage of air |
| auxiliary airfield | an airfield that functions in a subsidiary capacity |
auxiliary boiler
donkey boiler | (nautical) an extra boiler (as a ship's boiler that is used while the ship is in port) |
auxiliary engine
donkey engine | (nautical) a small engine (as one used on board ships to operate a windlass) |
auxiliary pump
donkey pump | a supplementary pump available if needed |
| auxiliary research submarine | a submarine for research purposes |
auxiliary storage
external storage
secondary storage | a data storage device that is not the main memory of a computer |
| Black Hole of Calcutta | a dungeon ( feet square) in a fort in Calcutta where as many as English prisoners were held overnight by Siraj-ud-daula, the next morning only were still alive |
bore
bore-hole
drill hole | a hole or passage made by a drill, usually made for exploratory purposes |
buttonhole
button hole | a hole through which buttons are pushed |
| ear hole | a hole (as in a helmet) for sound to reach the ears |
| finger hole | a hole for inserting a finger |
| finger hole | one of a series of holes in a woodwind instrument, pitch changes when a finger covers it |
foxhole
fox hole | a small dugout with a pit for individual shelter against enemy fire |
| funk hole | dugout as a place of safe retreat (when in a funk) |
glory hole
lazaretto | a small locker at the stern of a boat or between decks of a ship |
| hole | an opening deliberately made in or through something |
| hole golf hole | one playing period (from tee to green) on a golf course, he played holes |
| hole card | (poker) a playing card dealt face down and not revealed until the showdown |
| lubber's hole | hole in a platform on a mast through which a sailor can climb without going out on the shrouds |
| mouth hole | a hole (as in a ski mask) for the mouth |
| nail hole | a hole left after a nail is removed |
off-line equipment
auxiliary equipment | electronic equipment not in direct communication (or under the control of) the central processing unit |
posthole
post hole | a hole dug in the ground to hold a fence post |
posthole digger
post-hole digger | a shovel used to sink postholes |
| shot hole | drill hole for a charge of an explosive |
| smoke hole | a vent (as in a roof) for smoke to escape |
| sound hole | a hole in a soundboard (as of a violin) designed to resonate with the tones |
vent
venthole
vent-hole
blowhole | a hole for the escape of gas or air |
trap
cakehole
hole
maw
yap
gob | informal terms for the mouth |
| auxiliary verb | a verb that combines with another verb in a verb phrase to help form tense, mood, voice, or condition of the verb it combines with |
modal auxiliary verb
modal auxiliary
modal verb
modal | an auxiliary verb (such as `can' or `will') that is used to express modality |
| toad-in-the-hole | sausage baked in batter |
| auxiliary cell | a terrorist cell responsible for logistics, usually large and less compartmentalized than other terrorist cells |
| hole-in-the-wall | a small unpretentious out-of-the-way place, his office was a hole-in-the-wall |
watering place
watering hole
spa | a health resort near a spring or at the seaside |
| black hole | a region of space resulting from the collapse of a star, extremely high gravitational field |
| bolt-hole | a hole through which an animal may bolt when pursued into its burrow or den |
| bullet hole | a hole made by a bullet passing through it |
| gopher hole | a hole in the ground made by gophers |
| hole | an opening into or through something |
| hole hollow | a depression hollowed out of solid matter |
kettle hole
kettle | (geology) a hollow (typically filled by a lake) that results from the melting of a mass of ice trapped in glacial deposits |
| ozone hole | an area of the ozone layer (near the poles) that is seasonally depleted of ozone |
rabbit burrow
rabbit hole | a hole in the ground as a nest made by wild rabbits |
sinkhole
sink
swallow hole | a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof |
| swimming hole | a small body of water (usually in a creek) that is deep enough to use for swimming |
| water hole | a natural hole or hollow containing water |
aide
auxiliary | someone who acts as assistant |
air pocket
pocket
air hole | a local region of low pressure or descending air that causes a plane to lose height suddenly |