underway
1 of 2adjective
un·der·way ˌən-dər-ˈwā 
: occurring, performed, or used while traveling or in motion
underway replenishment of fuel
underway
2 of 2adverb
variants or less commonly under way
1
: in motion : not at anchor or aground
The ship was underway at dawn.
2
: into motion from a standstill
The train should be underway again soon.
3
: in progress : happening now
Preparations for the celebration are already underway.
A search is underway.
The season got underway with a bang.
Synonyms
Adverb
- afoot
- under weigh
See all Synonyms & Antonyms 
Word History
Etymology
Adverb
probably from Dutch onderweg, from Middle Dutch onderwegen, literally, under or among the ways
First Known Use
Adjective
1743, in the meaning defined above
Adverb
1720, in the meaning defined at sense 1