17-letter words containing p, i, n, f
- spatial frequency — the measure of fine detail in an optical image in terms of cycles per millimetre
- spiritus frumenti — whiskey.
- spoonbill catfish — flathead catfish.
- springfield rifle — a single-shot, breechloading .45-caliber rifle used by the U.S. Army from 1867 to 1893.
- terminal platform — (in the oil industry) an offshore platform from which oil or gas is pumped ashore through a pipeline
- traffic policeman — a policeman controlling traffic, esp while stationed at an intersection, or enforcing traffic regulations
- trapdoor function — a function defined from data by means of a mathematical procedure in such a way that it is easy to obtain the function when the data are known, but when the procedure and data are not known it becomes very difficult to determine the original data: used in cryptography, where the data are the characters of the plain text, or message, and the trapdoor function is the cryptogram.
- unconformity trap — An unconformity trap is a hydrocarbon trap where the closure is made by an unconformity (= a formation of rock layers which represents a gap in the geological record).
- unify corporation — (company) Developers of the Unify relational database. At one time, before Sybase, they were a competitor of Oracle, et al.
- unprofessionalism — not professional; not pertaining to or characteristic of a profession.