step-up (st?p??p?)adj.1. Increasing in steps or by stages.2. Electricity Serving to increase voltage: a step-up transformer.n. An increase in size, amount, or activity.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.step?-up` adj. 1. effecting an increase. 2. serving to increase voltage: a step-up transformer. n. 3. an increase or rise in rate or quantity. [1890?95] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.step-up1. In land operations, a procedure by which control is passed from an organization to an element of that organization which has been sent to a new location in order to maintain continuity of control during relocation(s) of that organization.2. In land operations, the element of an organization which is sent to carry out a step-up procedure.Dictionary of Military and Associated Terms. US Department of Defense 2005.