3. (Med.) A medicine that increases the strength, and gives vigor of
action to the system.
Tonic sol-fa (Mus.), the name of the most popular among letter systems
of notation (at least in England), based on key relationship, and hence
called "tonic." Instead of the five lines, clefs, signature, etc., of
the usual notation, it employs letters and the syllables do, re, mi,
etc., variously modified, with other simple signs of duration, of upper
or lower octave, etc. See Sol- fa.
Ton"ic*al (?), a. Tonic. [R.] Sir T. Browne.
To*nic"i*ty (?), n. (Physiol.) The state of healthy tension or partial
contraction of muscle fibers while at rest; tone; tonus.
To*night" (?), adv. [Prep. to + night] 1. On this present or coming
night.