мавсимӣ

мавсимӣ: seasonal

Понздаҳ ҳазор дона гулҳои мавсимӣ шинонида шуданд.
Fifteen thousand seasonal flowers were planted.
Булбул чун паррандаи мавсимӣ зимистонро дар мамлакатҳои гарм мегузаронад.
The nightingale as a seasonal bird spends the winter in warm countries.

Bonus:
мавсим: season (noun)
мавсимӣ: seasonal (adj.)
Adding the suffix -ӣ to a noun makes it an adjective.
бодҳои мавсимӣ: seasonal winds
коргари мавсимӣ: seasonal worker

ирсӣ

ирсӣ: hereditary

Гурӯҳи хуне, ки ирсӣ мебошад, аз падару модар ба фарзандон мегузарад.
Blood type, which is hereditary, is passed from father and mother to children.
Барои пешгирии бемориҳои ирсӣ ва маъюбияти кӯдак бояд аз никоҳи хешутаборӣ худдорӣ намуд. 
For the prevention of hereditary diseases and disabilities in children one must refrain from marriage with a close relative.

Bonus:
Synonyms: меросӣ

сиёҳ

сиёҳ: black

Мӯи шимпанзе сиёҳу сахт мебошад.
The hair of a chimpanzee is black and hard.
Дар кишвари Дания лолаи сиёҳро парвариш мекунанд.
In Denmark they grow black tulips.

Bonus:
абри сиёҳ: black cloud, rain cloud
рӯзи сиёҳ: black day i.e. sad day, day of disaster
тахтаи сиёҳ: blackboard
сип-сиёҳ: very black
If you need to review colours you can do it at Memrise: Tajik Colours. (You need to log in, but it is free.)

пуртаҷриба

пуртаҷриба: experienced

Боғбонҳои пуртаҷриба ниҳолҳоро парвариш мекунанд.
Experienced gardeners grow (tend to) the seedlings.
Ба назари ман, Дилшод Назаров варзишгари хеле пуртаҷриба аст.
In my opinion, Dilshod Nazarov is a very experienced sportsman.

Bonus:
пур (full) + таҷриба (experience) = пуртаҷриба (experienced, full of experience)
Пуртаҷриба can also be translated “talented”, which is possibly a better translation for the second sentence.
Dilshod Nazarov is a talented Tajik athlete who won the first ever Olympic medal for Tajikistan in 2016, competing in the hammer throw.
Пур is a very useful prefix to add to nouns to make adjectives. Here are more examples:
пурзаҳр: very poisonous (заҳр: poison)
пургап: talkative (гап: speech, talk)
пурнамак: salty (намак: salt)
пурсабр: very patient (сабр: patience)

баланд

баланд: loud, loudly

Ман бо овози баланд фарьёд задам.
I called with a loud voice.
Ҳар ду баланд хандиданд.
Both of them laughed loudly.

Bonus:
Баланд can also mean “high”, as in –
девори баланд: high wall
нархи баланд: high price
“dark” (for colours) as in –
кабуди баланд: dark blue
Learn more adjectives at Memrise: Adjectives (4 levels).

абрнок

абрнок: cloudy

Ҳаво имрӯз хеле абрнок шуд.
The weather today was very cloudy.
Дар вилояти Бадахшон ҳавои абрнок пешгӯйӣ гардидааст.
In the region of Badakhshon cloudy weather has been forecast.

Bonus:
Synonyms: абрӣ, абргирифта
Read the weather report in Tajik to learn other weather words. Here is one: Weather Channel, weather in Ozyankino, Russia. You can also search for the city where you live. Make sure language is set to Tajik.
асосан абрнок: mainly cloudy
қисман абрнок: partly cloudy
осмони абрнок: cloudy sky
ҳавои абрнок: cloudy weather

меҳрубон

меҳрубон: kind

Модарам бисёр зани меҳрубон ва дилсӯз буд.
My mother was a very kind and compassionate woman.
Муҳаббат пурсабр ва меҳрубон аст.
Love is patient and kind.

Bonus:
Describing things and people well is an advanced level skill. We need to get past the point of describing everything good as simply “нағз”. Making an effort to learn more adjectives is well worth it. Instead of describing your mother as a good woman, how would you describe her? Loving, gracious, compassionate, full of energy, welcoming, hot-tempered, strict? Ask your local friends to tell you the difference between a good teacher and a bad teacher, or between a good friend and a bad friend. That is a great way to learn more adjectives.
Here is a worksheet (pdf) that is designed for beginning or intermediate learners, but might also have some value for more advanced learners: Adjectives.

калонтар

калонтар: bigger

Ин боғ аз он боғ калонтар аст.
This garden is bigger than that garden.
Салим нисбат ба Раҳим калонтар аст.
Salim compared to Rahim is bigger.

Bonus:
калон: big
калонтар: bigger
калонтарин: biggest
For an intermediate lesson on comparatives and superlatives download this pdf: Comparatives and Superlatives.

миллӣ

миллӣ: national

Ман таомҳои миллиро дӯст медорам.
I love the national food.
27 июн дар Ҷумҳурии Тоҷикистон «Рӯзи Ваҳдати миллӣ» ҷашн гирифта мешавад.
On the 27th of June in the Republic of Tajikistan The Day of National Unity will be celebrated.

Bonus:
When you add “ро” or “и” or anything else to a word ending with ӣ, the ӣ is changed to an и.
Example: Суруди миллии Ҷумҳурии Тоҷикистон – The National Song of the Republic of Tajikistan.
Here is some info on National Unity Day – in English and in Tajik.

дуруст

дуруст: right, true

Гапатон дуруст.
You’re right. (What you said is right.)
Ин шаҳодат дуруст аст.
This testimony is true.

Bonus:
Opposite of дуруст is нодуруст – wrong, false.
Дуруст is used in some compound words, e.g.
тандуруст: healthy
дурустрафтор: well-behaved