Scrabble?! COLOGARITHMS

Definitions of COLOGARITHMS in various dictionaries:

In mathematics, the base-b cologarithm, sometimes shortened to colog, of a number is the base-b logarithm of the reciprocal of the number. It is equal to the negative base-b logarithm of the number. colog b ⁡ ( x ) = log b ⁡ ( 1 x ) = log b ⁡ ( 1 ) − log b ⁡ ( x ) = − log b ⁡ ( x ) {\displaystyle \operatorname {colog} _{b}(x)=\log _{b}\left({\frac {1}{x}}\right)=\log _{b}(1)-\log _{b}(x)=-\log _{b}(x)} In chemistry, a decimal cologarithm is indicated by the letter p. This usage originated with the quantity pH, defined as –log10 [H3O+]. Based on pH, the quantity pKa was later defined as –log10 Ka.