Frus"trate (?), a. [L. frustratus, p. p. of frustrare, frustrari, to deceive, frustrate, fr. frustra in vain, witout effect, in erorr, prob. for frudtra and akin to fraus, E. fraud.] Vain; ineffectual; useless; unprofitable; null; voil; nugatory; of no effect. "Our frustrate search." Shak.

Frus"trate (?), v. t. [imp. & p. p. Frustrated (?); p. pr. & vb. n. Frustrating.] 1. To bring to nothing; to prevent from attaining a purpose; to disappoint; to defeat; to baffle; as, to frustrate a plan, design, or attempt; to frustrate the will or purpose.

Shall the adversary thus obtain
His end and frustrate thine ?

2. To make null; to nullifly; to render invalid or of no effect; as, to frustrate a conveyance or deed.

Syn. -- To balk; thwart; foil; baffle; defeat.

• to disappoint or defeat
       It frustrates me to do all this work and then lose it all.
  
• to hinder
       My clumsy fingers frustrate my typing efforts.
  
• Student-Friendly Definition: When something is very difficult and it makes a person upset.
       "Jake was so frustrated by his homework that he slammed his book closed and threw it in the corner."