whimberry

From earlier winberry, apparently a variant of wineberry (Middle English winberie) with regular shortening of the first vowel before a consonant cluster; in wineberry, this was prevented or reversed due to analogy.
The assimilation of /nb/ to /mb/ seen in some forms is to be expected (compare hemp < Old English henep). Other forms show the influence of unrelated words; the consonantism of forms with initial wh- is probably due to the influence of whin, while windberry clearly represents remodelling as wind + berry.