pro-form 
noun Linguistics
A word or lexical unit which is dependent for its meaning on reference to some other part of the context, for example a pronoun or the verb do in she likes chocolate and so do I.
- pencil case
- pencil cedar
- pencil compass
- pencil crayon
- pencil flash
- pencil flashlight
- pencil flower
- pencil-knife
- pencil lead
- penciller
- pencil line
- pencilly
- pencil mark
- pencil microphone
- pencil moustache
- pencil-neck
- pencil-necked
- pencil pants
- pencil pine
- pencil pusher
- pencil-pushing
- pencil sharpener
- pencil skirt
- pencil someone in
- pencil something in