unexpectedly or without warning
inesperadamente o sin previo aviso (inesperadamente o sin previo aviso)
"My old friend called me out of the blue after ten years."
"Mi viejo amigo me llamó de la nada después de diez años." (Mi viejo amigo me llamó **de la nada** después de diez años.)
to express care or sympathy toward others
to analyze and solve a problem carefully; borrowed from prog...
to attack someone's most vulnerable point
to accept praise for something one did
to speak frankly or sincerely
to increase the level of risk or difficulty