What do we call those words that stand in for other verbs?

Solution 1:

According to Halliday and Hasan(1976:39), substitution is a kind of grammatical cohesion for clinging onto a kind of semantic relationship. In linguistics, 'pro' means 'for', an empty category. Pro-verb as opposed to proverb which professor Lawler explained in the comments is a coinage of Otto Jesperson in early twentieth century to explain what pronouns are to nouns, pro- verbs are to verbs. He even ventured to explain pro-adjective, pro-adverb or pro-infinitive.

In Grammar.about.com, Richard Nordquist while defining substitution in a light hearted moodrefers to Gelett Burgese's nonsense poem, "Purple Cow"(1985):

I never saw a purple cow,

I never hope to see one;

But I can tell you, any how

I'd rather see than be one.

ONE in this poem serves the function of nominal substitution or, simply put, is a pronoun. DO/BE/HAVE often discharge this pro-verb function (with IT/THAT). 'So' and 'Not' are often found to serve such dummy word function.

• Sunday the tenth looks pretty good, and, so does Monday the sixth.

However, as general words for any type of substitution or to avoid repetition Nordquist uses the term FILLER or ELLIPSIS SUBSTITUTION. It is better to use such general terms if there is no befitting term, say as is pronoun.