es·ca·late (ěs'kə-lāt') v.
es·ca·lat·ed, es·ca·lat·ing, es·ca·lates
v.
tr. To increase, enlarge, or intensify: escalated the hostilities in the Persian Gulf. v.
intr. To increase in intensity or extent: "a deepening long-term impasse that is certain to escalate"(Stewart L. Udall).
[Back-formation from escalator.] es'ca·la'tion n., es'ca·la·to'ry (-lə-tôr'ē, -tōr'ē) adj.