What is the meaning of Make_certain?

5-letter words containing

• 5-letter words containing r

• 5-letter words containing e

• 5-letter words containing i

• 5-letter words containing n

• 5-letter words containing a

5-letter words starting with

• 5-letter words starting with e

• 5-letter words starting with a

• 5-letter words starting with a

• 5-letter words starting with l

• 5-letter words starting with a

5-letter words in the middle

• 5-letter words in the middle i

• 5-letter words in the middle p

• 5-letter words in the middle o

• 5-letter words in the middle m

• 5-letter words in the middle e

5-letter words ending with

• 5-letter words ending with w

• 5-letter words ending with n

• 5-letter words ending with v

• 5-letter words ending with e

• 5-letter words ending with o

5-letter words excluding

• 5-letter words excluding r

• 5-letter words excluding u

• 5-letter words excluding r

• 5-letter words excluding a

• 5-letter words excluding i