stedefastly

• stedefasliche, stedefastli, stedefastliche, stedfastili, stedfastli, stedfastlie, stedfastliche, stedfastly, stedfastlych, stidefastli, stidefastly, stidfastly
• stedefæstliche, stedevastliche, studefestliche, studevastliche, studevestliche (Early Middle English)
• stedfastlich, stedfastlyk (Essex); stedevestliche, stedevestlyche (Kent); studefastliche, studefast-liche, studefastlych, studfastely, studfastelyche, studfastly (Southern, West Midland)

From stedefast +‎ -ly (adverbial suffix).

• IPA^(key): /ˈstɛːd(ə)ˌfastliː/, /ˈstɛd(ə)ˌfastliː/, /-lit͡ʃ(ə)/

stedefastly

1. Steadfastly, firmly, convincedly; without doubt.
2. Steadily, firmly; in a firm or steady way.
3. (of directives) Rigorously, exactly; without deviation.
4. Uninterruptedly, eternally; without halt.
5. (rare) Unmovingly, stationarily; in a still way.
6. (rare) Totally, fully; without exception.

• English: steadfastly
• Scots: steadfastly

• “sted-fastlī, adv.”, in MED Online, Ann Arbor, Mich.: University of Michigan, 2007.