flammable - Easily set on fire; capable of catching fire quickly.
flaunt - To treat or behave in a way that shows disregard for rules or norms
flaccid - Lacking strength, firmness, or resilience.
flaky - Unreliable or inconsistent in behavior, especially in keeping commitments.
flashback - A sudden, vivid memory of a past event, often triggered by something in the present. Often used in films and books.
finale - The last part of a piece of music, a performance, or a public event, especially when particularly dramatic or exciting.
flip - To turn over or rotate something quickly, especially with a sudden movement.
fluctuate - To change or vary irregularly, especially in amount or level.
fledgling - Referring to a process or person that is new, untested, and lacks experience.
flareup - A sudden outburst or intensification of something, especially violence or emotion.
flame - A hot, glowing body of ignited gas produced by something on fire; or a strong feeling, especially of passion, anger, or love.
flow - To move steadily and continuously, typically in a liquid, air, or smooth motion.