Dictionary.com
Thesaurus.com
Synonyms

alongside

American  
[uh-lawng-sahyd, uh-long-] / əˈlɔŋˈsaɪd, əˈlɒŋ- /

adverb

  1. along, by, at, or to the side of something.

    We brought the boat alongside.


preposition

  1. beside; by the side of.

    The dog ran alongside me all the way.

  2. Informal. alongside of, compared with.

    Alongside of his brother, he is no student at all.

alongside British  
/ əˈlɒŋˌsaɪd /

preposition

  1. (often foll by of) along the side of; along beside

    alongside the quay

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adverb

  1. along the side of some specified thing

    come alongside

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of alongside

First recorded in 1700–10; along + side 1