Eleven letter anagrams
| necessarian renaissance calligraphy graphically probationer reprobation cosmetician encomiastic considerate desecration deification edification peripatetic precipitate ethological theological incorporate procreation offuscation suffocation |
colonialist oscillation attentively tentatively enumeration mountaineer importunate permutation impressible permissible centerpiece centrepiece conditioner recondition description discerption reconnoiter reconnoitre interpreter reinterpret |
Found, spring 2000, in dictionary by dpd using process described here.