Sentence:  The purpose of this provision was thus explained in the Court 's opinion : `` Section 7 is designed to arrest in its incipiency not only the substantial <WSD>lessening</WSD> of competition from the acquisition by one corporation of the whole or any part of the stock of a competing corporation , but also to arrest in their incipiency restraints or monopolies in a relevant market which , as a reasonable probability , appear at the time of suit likely to result from the acquisition by one corporation of all or any part of the stock of any other corporation . 
Meaning of the word marked with <WSD> tags:  a change downward