It originates in the Latin re (back) + tenere (to hold). That led to the old French retenir and then in turn to Middle English reteynen, which became our word, retain.
For Scrabble fans, though, retains is a bit magical, for two reasons. First, it's one of the easier 7-letter words to find on your rack, since all of its letters are very common ones. If you find yourself with a rack full of low-scoring letters, take a quick glance to see if RETAINS is lurking.
Second, it has the most anagrams of any 7-letter Scrabble word -- eight other words! This gives you lots of options to maximize your score when playing these letters, or to get a bingo on the board at all when things start to crowd up.
Thus, it's good to take a look at the anagrams of RETAINS. Most competitive Scrabble players know these by heart:
- ANESTRI - periods of sexual dormancy; plural of ANESTRUS
- ANTSIER - comparative of ANTSY; even more jittery or hyper
- NASTIER - even more mean or hostile
- RATINES - RATINE is a heavy, loosely woven fabric; RATINES is the plural
- RETINAS - the RETINA is a part of the eye; RETINAS is the plural
- RETSINA - an alcoholic drink in Greece; a resin-flavored wine
"Athens :: Retsina Malmatina" (CC BY 2.0) by tomislavmedak
- STAINER - a person or a thing that stains
- STEARIN - the solid part of an animal or vegetable fat
This is an excellent list to retain in your memory!