underweighted

/AH0 N D ER0 W EY1 T IH0 D/
verb
  1. 1

    To underestimate the weight of.

  2. 2

    To give insufficient weight to (a consideration); to underestimate the importance of.

Source: https://en.wiktionary.org/wiki/underweight, https://en.wiktionary.org/wiki/underweighted