18-letter words containing a, s, f, e, p, i
- reinforced plastic — plastic with fibrous matter, such as carbon fibre, embedded in it to confer additional strength
- safety-deposit box — a lockable metal box or drawer, especially in a bank vault, used for safely storing valuable papers, jewelry, etc.
- saint peter's fish — another name for tilapia, taken from a Bible story about Saint Peter catching a fish with a coin in its mouth
- sampling frequency — sample rate
- seafloor spreading — a process in which new ocean floor is created as molten material from the earth's mantle rises in margins between plates or ridges and spreads out.
- self-contemplation — the act or process of thinking about oneself or one's values, beliefs, behavior, etc.
- self-deprecatingly — in a self-deprecating manner
- self-disparagement — the act of disparaging.
- self-preoccupation — the state of being preoccupied.
- self-tapping screw — a screw designed to tap its corresponding female thread as it is driven.
- soda-lime feldspar — plagioclase.
- stepping-off place — jumping-off place (def 2).
- sweptwing aircraft — an aircraft which has wings that are swept (usually) backwards
- to play favourites — to display favouritism
- wild passionflower — the maypop, Passiflora incarnata.