sun protection factor: the effectiveness of a sunscreen in protecting the skin from the sun's ultraviolet UVB radiation, as rated on a scale of increasing protectiveness, the number being the ratio of the radiation dose needed to produce minimal redness when using sunscreen compared to the dose needed to produce the same redness without sunscreen: An SPF of 15 will allow you to stay in the sun 15 times longer.
IS YOUR DESERT PLANT KNOWLEDGE SUCCULENT OR DRIED UP?
Cactus aficionados, don't get left in the dust with this quiz on desert plants. Find out if you have the knowledge to survive this prickly foray into the desert!
Question 1 of 7
This tall, horizontally branched cactus is probably the most recognizable cactus in Arizona. What is it called?
Words nearby SPF
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Example sentences from the Web for SPF
SPF is in our moisturizers, lip balms, eye creams, and make-up.
British Dictionary definitions for SPF (1 of 2)
sender policy framework: a mechanism designed to prevent an e-mail address being duplicated and used as a false address from which to send unsolicited e-mails
sun protection factor: an indicator of how effectively a sun cream, lotion, cosmetic, etc, protects the skin from the harmful rays of the sunSPF 25
British Dictionary definitions for SPF (2 of 2)
vet science specific pathogen free; denoting animals specially bred to ensure that they are free of specified diseases
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medical definitions for SPF
sun protection factor
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.