Dictionary.com
Thesaurus.com

suitcase vs. luggage

[soot-keys] / ˈsutˌkeɪs /

noun

suitcases plural
  1. a usually rectangular piece of luggage especially for carrying clothes while traveling.

[luhg-ij] / ˈlʌg ɪdʒ /

noun

luggage plural
  1. suitcases, trunks, etc.; baggage.