Frequency: The word is one of the 1500 most common words in English.
1.
You use ~ to emphasize that what you are saying applies more to one person, thing, or area than to any others.
Millions of wild flowers colour the valleys, ~ in April and May...
Re-apply sunscreen every two hours, ~ if you have been swimming.
= particularly
ADV: ADV with cl/group emphasis
2.
You use ~ to emphasize a characteristic or quality.
Babies lose heat much faster than adults, and are ~ vulnerable to the cold in their first month.
ADV: ADV adj/adv emphasis