
1) Carefully 2) Sparsely 
Found on 
https://www.crosswordclues.com/clue/thinly

1) Daintily 2) Delicately 3) Diaphanously 4) Flimsily 5) Gauzily 6) How most cold cuts are cut 7) How some insults are veiled 8) How some things are disguised 9) How some things are veiled 10) How something may be veiled 11) In a flimsy way 12) In a scanty way 13) In a small quantity or extent 14) Lightly 
Found on 
https://www.crosswordclues.com/clue/thinly

• (a.) In a thin manner; in a loose, scattered manner; scantily; not thickly; as, ground thinly planted with trees; a country thinly inhabited.
Found on 
http://thinkexist.com/dictionary/meaning/thinly/
 Thin'ly  adjective
Thin'ly  adjective  In a thin manner; in a loose, scattered manner; scantily; not thickly; as, ground 
 thinly planted with trees; a country 
 thinly inhabited. 
Found on 
http://www.encyclo.co.uk/webster/T/45

This is a vague term which is used ubiquitously. In general, if you place small seeds roughly 1.2 to 2.5cm (half an inch to an inch) apart then you won't go far wrong. Larger seeds (such as peas) are placed further apart. If the germination rate is high and many seedlings are wasted by later thinning, just sow thinner next time!
Found on 
http://www.gardeningdata.co.uk/glossary.php

[
adv] - without force or sincere effort 2. [adv] - without viscosity 3. [adv] - in a small quantity or extent 4. [adv] - in a widely distributed manner
Found on 
http://www.webdictionary.co.uk/definition.php?query=thinly
 thin adverb
thin adverb without viscosity; `the blood was flowing thin`
Found on 
https://www.encyclo.co.uk/local/20974
  No exact match found.