Definitions of sieve:

• noun:   a strainer for separating lumps from powdered material or grading particles
• verb:   distinguish and separate out
• verb:   check and sort carefully
• verb:   separate by passing through a sieve or other straining device to separate out coarser elements
• verb:   examine in order to test suitability
• name:  A surname (very rare: popularity rank in the U.S.: #78158)