SP.Taxonomy.TermSetItem.isAvailableForTagging property (sp.taxonomy)
Specifies the information about whether the TaxonomyItem appears in the tagging user interface.
Applies to: apps for SharePoint | SharePoint Foundation 2013 | SharePoint Server 2013
var value = SP.Taxonomy.TermSetItem.get_isAvailableForTagging()
SP.Taxonomy.TermSetItem.set_isAvailableForTagging(a)