
1) Allay 2) Assuage 3) Blend 4) Deaden 5) Ease 6) Ease up 7) Intenerate 8) Melt 9) Moderate 10) Quieten 11) Reduce 12) Relent 13) Soothe 14) Sweeten 15) Tame 16) Thaw 17) Unsteel 
Found on 
https://www.crosswordclues.com/clue/soften

1) Alleviate 2) Become less harsh 3) Become soft or softer 4) Change intensity 5) Cushion 6) Ease 7) Edit 8) Get mushy 9) Give in somewhat 10) Grow less adamant 11) Lessen in force or effect 12) Make gentler 13) Make less severe or harsh 14) Make soft or softer 15) Mellow 16) Mitigate 17) Mollify 18) Protect from impact 
Found on 
https://www.crosswordclues.com/clue/soften

• (v. i.) To become soft or softened, or less rude, harsh, severe, or obdurate. • (v. t.) To mollify; to make less fierce or intractable. • (v. t.) To compose; to mitigate; to assuage. • (v. t.) To make soft or more soft. • (v. t.) To palliate; to represent as less enormous; as, to soften a fault. • (v. t.) To make les...
Found on 
http://thinkexist.com/dictionary/meaning/soften/
 Sof'ten  intransitive verb
Sof'ten  intransitive verb  To become soft or softened, or less rude, harsh, severe, or obdurate. 
Found on 
http://www.encyclo.co.uk/webster/S/138
 Sof'ten  transitive verb
Sof'ten  transitive verb [ 
 imperfect & past participle   Softened ; 
 present participle & verbal noun   Softening .] To make soft or more soft. Specifically: -- 
 (a)  To render less hard; -- said of matter. « Their arrow's point the...
Found on 
http://www.encyclo.co.uk/webster/S/138

[
v] - make soft or softer 2. [v] - make soft or softer 3. [v] - become soft or softer
Found on 
http://www.webdictionary.co.uk/definition.php?query=soften

To change the texture of an ingredient or combined ingredients to make them softer or a room temperature.
Found on 
http://www.wrenscottage.com/kitchen/glossary.php

suavizar, esfumar
Found on 
https://www.encyclo.co.uk/local/22762
  No exact match found.