W

Week

An arbitrary period of days, usually seven days; approximately equal to the number of days counted between the four phases of the Moon. (See lunar phases.)

 

Wobble, polar

1. In current practice including the phraseology used in The Astronomical Almanac, it is identical to polar motion. 

2. In certain contexts it can refer to specific components of polar motion, e.g. Chandler wobble or annual wobble. (See polar motion.)