1) Anyhow 2) At any rate 3) Come rain or shine 4) Come what may 5) Disregarding 6) Disregardless 7) Even so 8) Heedless 9) In any event 10) Irregardless 11) Irrespective 12) Unheeding 13) Willy nilly 1) Careless 2) Heedless 3) In spite of everything 4) Thoughtless 5) Unheeding 6) Without regard to drawbacks 
• (a.) Having no regard; heedless; careless; as, regardless of life, consequences, dignity. • (a.) Not regarded; slighted.
Re·gard'less adjective 1. Having no regard; heedless; careless; as, regardless of life, consequences, dignity. « Regardless of the bliss wherein he sat.» Milton. 2. Not regarded; slighted. [ R.] Spectator. Syn. -- Heedless; negligent...
[adv] - in spite of everything
adjective (usually followed by `of`) without due thought or consideration; `careless of the consequences`; `crushing the blooms with regardless tread`irrespective adverb in spite of everything; without regard to drawbacks; `he carried on regardless of the difficulties`