рядко

• seldom, rarely; on rare occasions, once in a while
• много РЯДКО very rarely, hardly ever, once in a great while
• съвсем РЯДКО once in a blue moon
• РЯДКО населен sparsely/thinly inhabited/populated
• РЯДКО се вижда/намира (и пр.) it is rare to see/find (etc.), it is rarely that one finds/sees (etc.)
• РЯДКО се виждаме с него we see little of each other