Frequency Modulation. Using continuous, analogue, variation of the frequency of a radio signal to convey information, as in FM radio. Digital variant is FSK (frequency shift keying).
Found on http://www.encyclo.co.uk/visitor-contributions.php
Fetal movement. It may say 'FM felt' or 'FMF' on your notes. That means your baby had been felt to move. Found on https://www.encyclo.co.uk/local/22790
frequency modulation: a method of impressing a signal on a radio carrier wave by varying the frequency of the carrier wave. · a system of radio broadcasting by means of frequency modulation. · of, pertaining to, or utilizing such a system. Cf. AM. Found on https://www.infoplease.com/dictionary/fm