Creep

verb

1. To move slowly with the abdomen close to the ground.
2. Of plants, to grow across a surface rather than upwards.
3. To move slowly and quietly in a particular direction.
4. To make small gradual changes, usually in a particular direction.
5. To move in a stealthy or secret manner; to move imperceptibly or clandestinely; to steal in; to insinuate itself or oneself.