terms is a generic function
  which can be used to extract terms objects
  from various kinds of R data objects.
terms(x, ...)c("terms", "formula") which contains the
  terms representation of a symbolic model.  See
  terms.object for its structure.
"aovlist", and "terms"
  "formula" (see terms.formula):
  the default method just extracts the terms component of the
  object, or failing that a "terms" attribute (as used by
  model.frame).  There are print and labels methods for
  class "terms": the latter prints the term labels (see
  terms.object).
terms.object, terms.formula,
  lm, glm, formula.