21-letter words containing a, h, o, l, d
- to fly off the handle — If you fly off the handle, you suddenly and completely lose your temper.
- to let your hair down — If you let your hair down, you relax completely and enjoy yourself.
- to live hand to mouth — If someone lives hand to mouth or lives from hand to mouth, they have hardly enough food or money to live on.
- to play the race card — if someone plays the race card they bring up the issue of race in a discussion, perhaps for sympathy or to seek popularity by appealing to racist sentiment
- to rear its ugly head — If something unpleasant rears its head or rears its ugly head, it becomes visible or noticeable.
- trichloroacetaldehyde — chloral (def 1).
- up hill and down dale — strenuously and persistently
- weak head normal form — (reduction, theory) (WHNF) A lambda expression is in weak head normal form (WHNF) if it is a head normal form (HNF) or any lambda abstraction. I.e. the top level is not a redex. The term was coined by Simon Peyton Jones to make explicit the difference between head normal form (HNF) and what graph reduction systems produce in practice. A lambda abstraction with a reducible body, e.g. \ x . ((\ y . y+x) 2) is in WHNF but not HNF. To reduce this expression to HNF would require reduction of the lambda body: (\ y . y+x) 2 --> 2+x Reduction to WHNF avoids the name capture problem with its need for alpha conversion of an inner lambda abstraction and so is preferred in practical graph reduction systems. The same principle is often used in strict languages such as Scheme to provide call-by-name evaluation by wrapping an expression in a lambda abstraction with no arguments: D = delay E = \ () . E The value of the expression is obtained by applying it to the empty argument list:
- what the future holds — If you wonder what the future holds, you wonder what will happen in the future.
- wholesale price index — an indicator of price changes in the wholesale market
- wildlife photographer — someone that specializes in taking photographs of wild animals, especially in their natural habitats, and plants
- yellow-throated vireo — an olive-green vireo, Vireo flavifrons, of eastern North America, having a bright yellow throat and breast.