Mini crossword No 319

Across

1. Essentially Opaquer, finally Jennifer flows underground (7)
2. Yellow French article introduces start of week (5)
3. Lesley rotates in deaths engines (7)
4. Ordnance Survey go by another name in Japan (5)

Down

1. Perhaps when Hillary stepped off the top of Everest? (7)
2. Essential oil found in innards (4)
3. Appallingly, user led to escapees (7)
4. Every second dreams up a tool (4)