What's the difference between mammer and mummer?

Mammer

Definition:

• (v. i.) To hesitate; to mutter doubtfully.

Example Sentences:

• (1) Previously undetected analogies between the two proteins emerge as a result of selecting a common orientation in this mammer.

Mummer

Definition:

• (n.) One who mumms, or makes diversion in disguise; a masker; a buffon.

Example Sentences:

• (1) He managed to stay for five years, founded The Mummers, the first university drama group to admit women, and edited Granta.