писар

писар: son

Ӯ як писар ва чор духтар дошт.
He had one son and four daughters.
Вақте таваллуд кардани Элисобат фаро расид ва ӯ писаре зоид.
When the time came for Elizabeth to give birth, she gave birth to a son.

Bonus:
Notice in the first sentence that the word daughter, духтар, does not have a plural ending. In Tajik, if a noun follows a number, the noun does not take the plural ending.

Писар can also mean boy.

Some other family members:
модар: mother
падар: father
духтар: daughter
ака: older brother
додар: younger brother
апа: older sister
хоҳар: younger sister
модаркалон, бибӣ: grandmother
парадкалон, бобо: grandfather
набера: grandchild
тағо, амак: uncle
хола, амма: aunt

одам

одам: person, man, human

Он одамро намешиносам.
I don’t know that person.
Падараш одами иззатманд буда, ҳама ӯро ҳурмат мекарданд.
His father was an honourable man and everybody respected him.

Bonus:
одамизод: humankind
одамкуш: murderer
одамдузд: kidnapper
одамхӯрӣ: cannibalism

Одам is also the name of the first human, translated in English as Adam.

насл

насл: generation

Ҳамаи наслҳо аз Иброҳим то Довуд чордаҳ насл аст.
All the generations from Abraham to David is fourteen generations.
Глаукома хосияти ирсӣ дошта, аз насл ба насл мегузарад.
Glaucoma, having a hereditary quality, passes from generation to generation.

Bonus:
насли нави олимон: new generation of scientists
насли ҷавони ҳозира: younger generation (of today)
аз насл ба насл: from generation to generation

ятим

ятим: orphan

Аз ҳама гандатар се чиз аст: якум дуздӣ, дуюм ятимонро озор додан, сеюм бахилӣ. (Сотим Улуғзода)
Three things are worse than all: first theft, second to mistreat the orphans, third greed.
Ӯ дар тифлӣ аз падар ятим мондааст.
He was left an orphan in his childhood by his father (by his father’s death).

Bonus:
Synonym: сағир

ятимхона: orphanage