Either a style of dancing or simply playing Por Medio on the guitar.
Literally a "lift', a subida is a quickening of tempo, which can be gradual or sudden.
The tonic is the first note of the scale used to build a piece of music. This note, and corresponding chord, gives us a sense of resolution in music. We often refer to this as "home base." For example, in the key of A, the root of the main chord is A, therefore the tonic is A.
Flamenco strumming - any time you use the back of the nails of your fingers (not the thumb) to play a note.
Flick out each finger as if you are flicking a bug off your knee. We are trying for individual, percussive, and rhythmic strokes with each finger, rather than just unfurling your finger...