From German - English Ding/FreeDict dictionary ver. 1.9-fd1:
Stabsfeldwebel /ʃtˈapsfəldvˌeːbəl/ (StFw. /ˌɛstˈeː ˌɛfvˈeː/) <masc, n, sg>
[Dt.] Warrant Officer Class 2 <n> [Br.] WO2, /vˌoː tsvˈaɪ/ , Master Sergeant <n> [Am.] MSG, /(en)ˌɛmˌɛsdʒˈiː(de)/ , First Sergeant <n> [Am.] 1SG, /ˈaɪns ˌɛsɡˈeː/ , Master Warrant Officer <n> [Can.]
Note: rank
Synonyms: Offiziersstellvertreter, Adjutant Unteroffizier