What is the difference between eye and light? 

The difference is that eye is the dark brown center of a black-eyed susan flower while light is a cross-light in a double acrostic or triple acrostic.

What is the difference between hay and mote? 

The difference is that hay is a circular country dance while mote is a place of meeting for discussion.

 What is the difference between slide and glib? 

The difference is that slide is to cause to move in continuous contact with a surface while glib is to castrate; to geld; to emasculate.

That is the difference is that slide is an item of play equipment that children can climb up and then slide down again while glib is a mass of matted hair worn down over the eyes. 

Sill can be a young herring or sill can be the shaft or thill of a carriage. But as an adjective safe is not in danger. Safe is free from harm's reach.