- Category of red/orange stars including Arcturus and Aldebaran, which have a surface temperature in the 3500–5000K region and spectra with large numbers of metal lines. K stars are the coolest apart from the M class.
- In economic models, K is commonly used to represent "capital." This is presumably due to the fact that German for capital is kapital, and also the fact the C is more commonly used to represent consumption.
- symbol forcapital
- noun one thousand. This abbreviation existed in limited slang usage in the 1970s (based on the k of kilo), but it was its use in computer jargon (to mean a storage capacity of 1,024 bytes) which was first transposed to express sums of money when discussing fees or salaries. It then entered general colloquial use in the 1980s.
- noun a knighthood, from the initial letter, or that of KBE, KCMG, etc.
- chemical symbol forKalium
- symbol forknot(s)
(written as k)